If they're there only when they need you, they don't value you they use you

Usefulness based friendship means you are important to them only when they need you. When they need help, emotional, academic, social, then they come to you. You help them instantly because your heart is clear. But when you need support, your message is on their phone. You are not their priority, you are only their convenience. And slowly you start realizing that you are always available, but they can't even take a moment for you.